Three-dimensional display system

1. A method of displaying three-dimensional images, comprising: providing a projection screen having a spatial filter defining a predetermined angularly-responsive reflective surface function; determining the left and right eye locations of at least one observer in proximity with the projection screen; projecting left and right sub-images of a three-dimensional image toward the projection screen; and angularly and intensity modulating the left and right sub-images respectively in coordination with the predetermined angularly-responsive reflective surface function to define respective discrete light paths that respectively direct the left and right sub-images to reflect from the projection screen to the respective left and right eye locations to provide a three-dimensional viewing experience.

2. The method as claimed in claim 1 wherein the angularly-responsive reflective surface function is sinusoidal.

3. The method as claimed in claim 1 wherein modulating the left and right sub-images respectively in coordination with the predetermined angularly-responsive reflective surface function constitutes the projection screen as a programmable mirror that is a spatial filter.

4. The method as claimed in claim 1 further comprising tracking movement of the eye locations relative to the projection screen.

5. The method as claimed in claim 1 further comprising tracking predetermined observer characteristics in a virtual volume to provide feedback for interactive, observer-actuated control inputs.

6. The method as claimed in claim 1 wherein determining the left and right eye locations and projecting left and right sub-images further comprises projecting a scan image sub frame in concert with projecting the left and right sub-images.

7. The method as claimed in claim 1 wherein: projecting left and right sub-images further comprises projecting left and right image sub frames, and determining the left and right eye locations further comprises projecting a scan image sub frame in concert with projecting the left and right image sub frames to determine the left and right eye locations.

8. The method as claimed in claim 1 further comprising: tracking the observer with a scan image sub frame; and utilizing the scan image sub frame to sweep an entire target area in which the observer is being tracked.

9. The method as claimed in claim 1 further comprising: tracking the observer with a scan image sub frame; and utilizing the scan image sub frame to sweep a known position of the observer.

10. The method as claimed in claim 1 further comprising: tracking the observer with a scan image sub frame; and adapting the number and the rate of the scan image sub frames in response to the degree and rate of movement of the observer.

11. The method as claimed in claim 1 further comprising: determining the relationship between the observer and the projection screen as the distance z between the observer and the projection screen; and determining the x,y,z locations of predetermined observer characteristics in at least one corresponding x,y plane that is parallel to the plane of the projection screen at distance z therefrom.

12. The method as claimed in claim 1 further comprising constituting a predetermined virtual display volume in front of the projection screen as a virtual volume for three-dimensional interactions.

13. The method as claimed in claim 1 further comprising constituting a predetermined virtual display volume in front of the projection screen as a virtual volume for three-dimensional interactions, observer interfaces, and observer input in conjunction with three-dimensional stereoscopic projection and viewing.

14. The method as claimed in claim 1 wherein modulating the left and right sub-images further comprises turning the sub-images on and off in respective image modulators to control optical projection into the observer's left and right eyes.

15. The method as claimed in claim 1 wherein modulating the left and right sub-images further comprises masking or gating out projection of the sub-images at those times when the sub-images are not aimed for reaching the observer's eyes.

16. The method as claimed in claim 1 wherein modulating the left and right sub-images further comprises modulating the scan velocity of a scanning beam in at least one of the horizontal and vertical directions.

17. The method as claimed in claim 1 wherein modulating the left and right sub-images further comprises correlating with the normal of the surface function.

18. The method as claimed in claim 1 wherein: modulating the left and right sub-images further comprises correlating with the normal of the surface function; and projecting left and right sub-images toward the projection screen further comprises projecting an incident light beam to each respective normal location for the corresponding pixel that is to be projected at that moment to and from that normal location.

19. The method as claimed in claim 1 wherein projecting left and right sub-images toward the projection screen further comprises projecting an incident light beam to each respective normal location for the corresponding pixel that is to be projected at that moment to and from that normal location, the incident beam having a width less than half the distance between the reflection points X L and X R of the pixel, wherein X L represents a reflection point corresponding to the left eye of the at least one observer and X R represents a reflection point corresponding to the right eye of the at least one observer.

21. The method as claimed in claim 1 further comprising determining an angle of a normal of the surface function that is correct for aiming a reflected beam into an eye of the observer using the equation: δ OP ⁡ ( x ) = δ O + δ P 2 = 1 2 · ( tan ⁡ ( L P - x L PS - Z OFF + Z 0 · sin ⁡ ( k 0 · x ) ) + tan ( ⁢ L O - x L OS - Z OFF + Z 0 · sin ⁡ ( k 0 · x ) ) ) + π 2 , wherein: δ Op is the angle of the normal of the surface function; δ O is the angle of the reflected light beam measured from the plane of the projection screen; δ p is the angle of a projected light beam measured from the plane of the projection screen; L P is the horizontal displacement of the projector; L PS is the vertical displacement of the projector; L O is the horizontal displacement of the observer; L OS is the vertical displacement of the observer; Z OFF is the average thickness of the projection screen; and Z 0 is the difference between the average thickness and the maximum thickness of the projection screen, x is the horizontal displacement along the surface of the projection screen; and k 0 =2·π÷λ P wherein λ P is the length of a pixel that is to be projected to and from the normal location.

22. The method as claimed in claim 1 further comprising encoding a modulation function into the surface of the projection screen to cause predetermined target deflection angles to be hit when scanning the projection screen at constant velocity.

23. The method as claimed in claim 1 further comprising: distinguishing between observers and non-observers; and projecting images only to targets having predetermined defining characteristics.

24. The method as claimed in claim 1 further comprising uniquely identifying individual observers based upon distinctive personal characteristics.

25. The method as claimed in claim 1 further comprising: uniquely identifying individual observers based upon distinctive personal characteristics; storing personalized observer preferences; and customizing the observer's experiences according to the preferences associated with that observer including at least one of: automatically authenticating the observer, personally greeting the observer, providing a customized desktop for that observer, providing customized control responses for that observer, and resuming a three-dimensional display where the three-dimensional display had been previously stopped.

26. The method as claimed in claim 1 further comprising automatically aligning the projection screen, the observer, and the projecting of the left and right sub-images, by: scanning and determining the locations of the projection screen and the observer; and adjusting the modulating in accordance with the projection screen location that is determined.

27. The method as claimed in claim 1 further comprising automatically aligning the projection screen, the observer, and the projecting of the left and right sub-images, by: scanning and determining the locations of the projection screen and the observer; recording at least one projection angle that reflects at least one projected sub-image to a predetermined location; and adjusting the modulating based thereon.

28. A three-dimensional display system, comprising: a projection screen having a spatial filter defining a predetermined angularly-responsive reflective surface function; apparatus for determining the left and right eye locations of at least one observer in proximity with the projection screen; apparatus for projecting left and right sub-images of a three-dimensional image toward the projection screen; and apparatus for angularly and intensity modulating the left and right sub-images respectively in coordination with the predetermined angularly-responsive reflective surface function to define respective discrete light paths that respectively direct the left and right sub-images to reflect from the projection screen to the respective left and right eye locations to provide a three-dimensional viewing experience.

29. The system as claimed in claim 28 wherein the angularly-responsive reflective surface function is sinusoidal.

30. The system as claimed in claim 28 wherein the apparatus for modulating the left and right sub-images respectively in coordination with the predetermined angularly-responsive reflective surface function constitutes the projection screen as a programmable mirror that is a spatial filter.

31. The system as claimed in claim 28 further comprising apparatus for tracking movement of the eye locations relative to the projection screen.

32. The system as claimed in claim 28 further comprising apparatus for tracking predetermined observer characteristics in a virtual volume to provide feedback for interactive, observer-actuated control inputs.

33. The system as claimed in claim 28 wherein the apparatus for determining the left and right eye locations and projecting left and right sub-images further comprises apparatus for projecting a scan image sub frame in concert with projecting the left and right sub-images.

34. The system as claimed in claim 28 wherein: the apparatus for projecting left and right sub-images further comprises apparatus for projecting left and right image sub frames, and the apparatus for determining the left and right eye locations further comprises apparatus for projecting a scan image sub frame in concert with projecting the left and right image sub frames to determine the left and right eye locations.

35. The system as claimed in claim 28 further comprising apparatus for: tracking the observer with a scan image sub frame; and utilizing the scan image sub frame to sweep an entire target area in which the observer is being tracked.

36. The system as claimed in claim 28 further comprising apparatus for: tracking the observer with a scan image sub frame; and utilizing the scan image sub frame to sweep a known position of the observer.

37. The system as claimed in claim 28 further comprising apparatus for: tracking the observer with a scan image sub frame; and adapting the number and the rate of the scan image sub frames in response to the degree and rate of movement of the observer.

38. The system as claimed in claim 28 further comprising apparatus for: determining the relationship between the observer and the projection screen as the distance z between the observer and the projection screen; and determining the x,y,z locations of predetermined observer characteristics in at least one corresponding x,y plane that is parallel to the plane of the projection screen at distance z therefrom.

39. The system as claimed in claim 28 further comprising a predetermined virtual display volume in front of the projection screen constituted as a virtual volume for three-dimensional interactions.

40. The system as claimed in claim 28 further comprising a predetermined virtual display volume in front of the projection screen constituted as a virtual volume for three-dimensional interactions, observer interfaces, and observer input in conjunction with three-dimensional stereoscopic projection and viewing.

41. The system as claimed in claim 28 wherein the apparatus for modulating the left and right sub-images further comprises apparatus for turning the sub-images on and off in respective image modulators to control optical projection into the observer's left and right eyes.

42. The system as claimed in claim 28 wherein the apparatus for modulating the left and right sub-images further comprises apparatus for masking or gating out projection of the sub-images at those times when the sub-images are not aimed for reaching the observer's eyes.

43. The system as claimed in claim 28 wherein the apparatus for modulating the left and right sub-images further comprises apparatus for modulating the scan velocity of a scanning beam in at least one of the horizontal and vertical directions.

44. The system as claimed in claim 28 wherein the apparatus for modulating the left and right sub-images further comprises apparatus for correlating with the normal of the surface function.

45. The system as claimed in claim 28 wherein: the apparatus for modulating the left and right sub-images further comprises apparatus for correlating with the normal of the surface function; and the apparatus for projecting left and right sub-images toward the projection screen further comprises apparatus for projecting an incident light beam to each respective normal location for the corresponding pixel that is to be projected at that moment to and from that normal location.

46. The system as claimed in claim 28 wherein the apparatus for projecting left and right sub-images toward the projection screen further comprises apparatus for projecting an incident light beam to each respective normal location for the corresponding pixel that is to be projected at that moment to and from that normal location, the incident beam having a width less than half the distance between the reflection points X L and X R of the pixel, wherein X L represents a reflection point corresponding to the left eye of the at least one observer and X R represents a reflection point corresponding to the right eye of the at least one observer.

48. The system as claimed in claim 28 further comprising circuitry for determining an angle of a normal of the surface function that is correct for aiming a reflected beam into an eye of the observer using the equation: δ OP ⁡ ( x ) = δ O + δ P 2 = 1 2 · ( tan ⁡ ( L P - x L PS - Z OFF + Z 0 · sin ⁡ ( k 0 · x ) ) + tan ( ⁢ L O - x L OS - Z OFF + Z 0 · sin ⁡ ( k 0 · x ) ) ) + π 2 , wherein: δ OP is the angle of the normal of the surface function; δ O is the angle of the reflected light beam measured from the plane of the projection screen; δ P is the angle of a projected light beam measured from the plane of the projection screen; L P is the horizontal displacement of the projector; L PS is the vertical displacement of the projector; L O is the horizontal displacement of the observer; L OS is the vertical displacement of the observer; Z O is the average thickness of the projection screen; Z 0 is the difference between the average thickness and the maximum thickness of the projection screen, x is the horizontal displacement along the surface of the projection screen; and k 0 =2÷λ P wherein λ P is the length of a pixel that is to be projected to and from the normal location.

49. The system as claimed in claim 28 further comprising a modulation function encoded into the surface of the projection screen to cause predetermined target deflection angles to be hit when scanning the projection screen at constant velocity.

50. The system as claimed in claim 28 further comprising apparatus for: distinguishing between observers and non-observers; and projecting images only to targets having predetermined defining characteristics.

51. The system as claimed in claim 28 further comprising apparatus for uniquely identifying individual observers based upon distinctive personal characteristics.

52. The system as claimed in claim 28 further comprising apparatus for: uniquely identifying individual observers based upon distinctive personal characteristics; storing personalized observer preferences; and customizing the observer's experiences according to the preferences associated with that observer including at least one of: automatically authenticating the observer, personally greeting the observer, a customized desktop for that observer, customized control responses for that observer, and resuming a three-dimensional display where the three-dimensional display had been previously stopped.

53. The system as claimed in claim 28 further comprising apparatus for automatically aligning the projection screen, the observer, and the apparatus for projecting left and right sub-images, by: scanning and determining the locations of the projection screen and the observer; and adjusting the apparatus for modulating in accordance with the projection screen location that is determined.

54. The system as claimed in claim 28 further comprising apparatus for automatically aligning the projection screen, the observer, and the apparatus for projecting left and right sub-images, by: scanning and determining the locations of the projection screen and the observer; recording at least one projection angle that reflects at least one projected sub-image to a predetermined location; and adjusting the apparatus for modulating based thereon.